Purified gambier (Uncaria gambir Roxb.) is potential for treating hypertension based on its antioxidant bioactivity. In this study, we investigated the antihypertensive performances of purified gambier on hypertensive rats and the correlation with its antioxidant activity. Methods: Rats (2-3 months old and the bodyweight of 200-250 g) were divided into five groups. Groups 1, 2, and 3 were treated orally with water suspension of purified gambier at doses of 2.5; 5; and 10 mg/kg BW once a day for

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... 14 days, group 4 and 5 were acted as positive control (treated with vehicle) and captopril treated group (comparison) respectively. The systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), heart rate (HR), blood flow (BF) and blood volume (BV) were recorded once a day before and 1,3,7 and 14 days after commencement. The blood was taken before and at the end of recording for the plasma NO measurement. Two-way ANOVA was used to analyze the changes of those parameters, except for plasma NO analyzes by one-way ANOVA, followed by Duncan multirange test (95% confidence interval). Results: The study showed that significant antihypertensive effects (p<0.05), influenced by doses and gambier administration duration. The plasma NO of animals was increased after administration of purified gambier (p<0.05), although there was no significant difference in plasma NO in doses variation. Conclusion: These indicated that purified gambier proceed antioxidant associated antihypertensive effects at doses of 2.5 – 10 mg/kg BW when administered for 14 days on the salt-prednisone induced hypertensive rats. KEYWORDS: antioxidant, antihypertensive, purified gambier, Uncaria gambir Roxb., salt-prednisone induced, hypertension rat